for all, here's an interactive town map of Muenster

for Andreas: I had a look at the map (it has a street search function): Overbergstr. is so close that I am ashamed I didn't know. Ten minutes walk from me. Go to the search function of the twon map, enter Overbergstr. and as soon as you have the map click on the arrow pointing exactly to the East. You'll then see a map that has both Overbergstr. and Wiener Str. in it and you can zoom in or out to see where that is in general.

Wolfgang